Field of the Invention
The present invention relates to a vehicle rotating electrical machine, and for example, relates to a rotating electrical machine mounted in a vehicle or the like and having a cooling fan rotated integrally with a rotor.
Description of the Related Art
There is an existing vehicle alternating current generator that generates cooling air using a cooling fan rotated integrally with a rotor in order to cool coil ends of a multiple of stator coils disposed on a radial direction outer side of a rotor. This kind of existing vehicle alternating current generator is such that a structure wherein a recess portion is provided in a housing opposing the coil ends of the stator coils in an axial direction has been proposed in order to improve the cooling performance of the coil ends by the cooling air from the cooling fan. In this way, the existing vehicle alternating current generator is such that, by a recess portion being provided in the housing, the width of a cooling air channel formed between the coil ends and the housing can be increased, whereby an improvement in the coil end cooling performance can be achieved (for example, refer to Patent Document 1).
Meanwhile, there is an existing generator such that the connection strength between a generator frame and amount stay (stay portion) is increased, vibration of a rotor, stator, or the like is prevented from increasing, and rotational fluctuation of the rotor is prevented. This kind of existing generator is such that a stay portion having a supported portion provided on an outer periphery of a cylindrical portion of a frame includes a connection member that extends from an inner side portion of the supported portion toward an outer peripheral side of the cylindrical portion, thereby connecting the stay portion and frame. Also, the connection member has an inclined face inclined with respect to a face perpendicular to an axis of rotation (for example, refer to Patent Document 2).
[Patent Document 1] JP-A-2015-159723
[Patent Document 2] Japanese Patent No. 2,924,689
However, in recent years there is a strengthening trend for demands with respect to vehicle rotating electrical machines (vehicle alternating current generators) to increase; demands for, of course, an increase in cooling performance, and at the same time, demands for restricting vibration and rotational fluctuation. With regard to a mount stay (stay portion) assembled in an engine, a frame-side end portion of the connection member blocks the greater part of a radial direction outer side of an exhaust port on the outer periphery of the frame cylindrical portion when the kind of strengthening using an inclined face described in Patent Document 2 is employed.
When an intermediate frame portion, between which and a blade of the fan disclosed in Patent Document 1 there is a narrow gap, and a channel expanded in an axial direction continuing from an outer diameter side inclination of the intermediate frame portion are applied in response to an exhaust port whose radial direction outer side is partially blocked as heretofore described, the following problems occur. Firstly, when the direction of cooling air fed into the housing from an air intake changes to a radial direction in order to pass along the channel formed between the coil ends and the front side housing, the cooling air is biased considerably from the axial direction to the axial center. Then, suctioned air that flows around and is drawn further inside the vehicle rotating electrical machine than the intermediate frame portion, which protrudes into the housing, is deflected and discharged, as a result of which a problem occurs in that the air nears the air intake and is suctioned again. The occurrence of this problem is particularly noticeable when the air intake is opened to a large size adjacent to an exhaust port whose radial direction outer side is blocked, that is, when the kind of thin spoke shown in FIG. 2 of Patent Document 1 is not configured. Re-suctioning of air that has once been drawn inside the vehicle rotating electrical machine is certain to cause a reduction in cooling performance.